U.S. Pat. No. 4,559,009, issued Dec. 17, 1985, assigned to Hauck Manufacturing Co. of Lebanon, Pa., and which is incorporated herein by reference, discloses a conventional aggregate dryer burner known in the art. The prior art burner, which uses a low pressure air oil atomizer, depends solely on a main combustion air blower to generate the pressure required to atomize fuel oil.
While this prior art burner generally works well, the 50-cycle air blowers found in many areas of the world produce air having a pressure of 24 osig. Air supplied at 24 osig air from a 50-cycle blower works well with the conventional aggregate dry burner for light oils, but 24 osig air does not effectively burn heavier oils. In order to achieve a higher burner discharge pressure of about 2 to 2.25 psig necessary to properly combust the heavier oils, since a 60-cycle blower cannot readily be adapted for use in these parts of the world, the air blower has to be mechanically altered to produce higher pressure air.
Compressed air oil atomizers and flame stabilization are also well known in the art. One type of compressed air oil atomizer, used in a burner in which 100 percent of the combustion air is provided through the burner assembly, is disclosed in Reissue application Ser. No. 10/387,006, filed Mar. 12, 2003, which originally issued as U.S. Pat. No. 6,488,496 B1, issued Dec. 3, 2002 (the “'006” Application), which is assigned to Hauck Manufacturing Co. of Lebanon, Pa. and which is hereby incorporated by reference. As taught in the '006 Application, primary air is generally supplied to the burner at a pressure of 36 osig.
What is needed is a burner assembly and method that permits the use of heavy oil with lower pressure main combustion air produced by 50-cycle power sources as are found in many areas of the world for air blowers.